The light brigade

By Arnie Katz

Most CFLs have become very reliable. They last much longer than incandescent bulbs and use a quarter to a third as much electricity.

Q: I’ve been seeing LED light bulbs in the stores lately. They claim they’ll save a bunch of money, but will they really? Will they actually last as long as they say? I got burned by buying some CFLs a few years ago that didn’t last very long, and I don’t want to make the same mistake again.

A: These are excellent questions. Let’s first talk about how long light bulbs will last. There’s a standard procedure for how long manufacturers can claim their light bulb will last. Basically, they put a bunch of bulbs in sockets and turn them on, let them run for three hours, turn them off, turn them back on for three hours and continue to do that until half the bulbs have burned out. That point — where half the bulbs have burned out and half are still on — is called the average life of the bulbs. That means you can expect half of the bulbs to burn out quicker than that average life number and half to last longer. If you typically have the light on for less than three hours at a time, it will probably not last as long.

LEDs are tested a bit differently since they don’t really “burn out.” Instead, they get dimmer over time, and the “average life” is when they’ve dimmed to the point where most people will notice. Yes, that’s a bit fuzzy.

The incandescent light bulb most of us grew up with was essentially unchanged for more than 100 years. The companies that made them had vast experience and learned how to have excellent quality control. As a result, these bulbs rarely fail prematurely, and most of the products last close to the average life on the label.

When new products are introduced, they bring new problems, and it often takes a while to work out the bugs in the system. Sometimes, this leads to less than ideal quality control and product failures.

CFLs are a classic example of this. The first ones I purchased in the 1980s cost $25 each. When I ran the numbers, the combination of much longer life and energy savings convinced me they were a good investment. Most of them lasted at least as long as promised and turned out to be a good value. (Yes, I know, thinking of light bulbs as an investment is a little strange.)

There were some, however, that failed early — very early. Most of those were much cheaper than the name brand bulbs. Clearly, I got what I paid for.

Over time, most CFLs have become very reliable. They last much longer than incandescent bulbs and use a quarter to a third as much electricity, making them a much better investment.

There are still some issues to consider. Does the bulb put out enough light? As I get older, I need more light just to see as well as I used to with less light. Brighter, higher wattage CFLs may do the trick, but you need to install one in your lamp or fixture to make sure.

Some folks have problems with the color of some CFLs. Again, buy one to test in your house and see how you feel about it. There are now a lot of different brands on the market, with different qualities. If you try one you don’t like, try another brand. You no longer have to take out a loan to buy these things — they’ve gotten much more affordable in recent years.

LEDs are about where CFLs were a few years ago. We’re just starting to see more products on the market. They’re still quite expensive, but the prices are coming down. Almost all of the independent testing verifies they should last at least 25 times longer than the old incandescent and use much less electricity than even the CFLs. There are a lot of different products out there, so if you try one and you don’t like it, try something else.

Now that we’re well into the 21st century, maybe it’s time to say thanks and farewell to Mr. Edison’s 19th-century light bulb.

About the Author

Arnie Katz is the former building science consultant for Advanced Energy in Raleigh. advancedenergy.org

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Energy Efficiency Tip

Replacing just four 75-W incandescent lightbulbs with four 23-W compact fluorescent equivalents will save almost $200 over life of the bulbs.